Welded blade structure



Patented July 1, 1947 WELDED BLADE STRUCTURE Robert C. Allen, Wauwatosa. Wis., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Continuation of application Serial No. 401,726,

July 10, 1941. Serial No. 604,594

. Claims.

This application is a continuation o! my copending application Serial No. 401,726, illed July 10, 1941, and the invention disclosed herein relates to blade assemblies of the type embodied in elastic iluid turbines and the like, and has for its obiect the provision of a simple and inexpensive blade assembly affording a rigid and durable connection of great strength between the base ends of the blades and the periphery oi' the rotor disk or other element to which such ends of the blades are attached.

More particularly, the disclosed invention is directed to the provision of an improved blade assembly wherein the blades have enlarged and relatively massive base portions disposed in contiguous row forming relation with their base ends presenting an approximately continuous ring substantially equal in width to and coextensively opposing a peripheral blade mounting portion presented by a rotor disk or other blade supporting; element, and wherein substantially the entire base end of all of the blades is in fused coextensive union with substantially the entire blade mounting portion of the rotor disk or other element.

ln general, the peripheral portion of the rotor disk or other element and the base ends of the blades may be formed to present plain opposed surface portions in order to reduce costs, and when thus formed, may be readily fusibly united by the method hereinafter disclosed and made the subject of a divisional application, Serial No. 431,- 469, illed February 19, 1942.

And the invention accordingly consists of elements constructed and united to form a blade assembly oi the character more fully set forth in the detailed description and appended claims, reference being had to theaccompanying drawing, in which:

Fig. l is a side elevation of a blade assembly embodying the invention;

Fig. 2 is e. perspective view of the form of blade employed;

Figs, 3-6 inclusive, illustrate various stages in the construction of a blade assembly made in accordance with the invention; and

Fig. 7 is a section through a blade taken on line VII- VII of Fig. 5;

Fig. il is a section through a series of blades taken on line VDI-VIII of Fig. 5.

Referring to the drawings, and particularly Figs. 1, 2, 6, 'I and 8, itis seen that the blade'assembly l, which represents a portion of a circumferential blade row, comprises a spindle or rotor disk member l, a series of impulse type blades 3 having their opposite ends abruptly enlarged to This application July I2, 1945.

present relatively massive integral shroud and base portions l and t, respectively, and a weld or fused metal bond 1 forming the sole connection between the base portion t oi each blade 3 and the periphery oi the disk 2. As shown in Figs. 1 and 8, the shroud and base portions are abuttlngly engaged to position and maintain the fluid engaging surfaces on adjacent blades correctly spaced to form therebetween the fluid conilning passages B. The disk 2 and the blades l are preferably shaped to present a single surfaced periphery and single surfaced base ends, respectively; i. e.. a surface which is free of any projection or recess abruptly interrupting the continuity of the surface, and therefore the expression single surface as herein used includes surfaces which are either plane or curved, these surfaces being either perpendicular or oblique relative to the edges and to the side surfaces of a blade base or to the side surfaces of a spindle disk or the like, as this type of construction materially reduces costs.

The blade assemblies are preferably formed by placing a chill ring member S of inverted T-shape in cross section and the blades 3 on a suitable jig H (the particular form and the detailed construction of the jig may be varied as desired) and manipulating the clamping means l2 provided thereon to securely hold the blades 3 and the ring member 9 in the relation shown in Fig. 3. The assembly comprising the jig Il, blades 3 and ring member 8 is then associated with the disk 2 in the manner shown in Fig. 4 and secured in this position by any suitable means (not shown). The chill ring member 9 in `addition to the usual functions of such members also acts to correctly position the blades 3 relative to the peripheral surface on the disk 2; i. e., the chill ring member 9 which preferably covers approximately one-half of the width of the peripheral surface on the disk 2 and which is engaged by a. corresponding portion of the underside surface of the blade base 8, maintains the remaining portion of the underside surface of the blade base 6 disposed in spaced overlying relation with respect to the exposed portion of the peripheral surface on said disk. The next step is to deposit the weld metal l in the circumferentially extending channel or space It defined by the exposed portion of the underside surface of the blade base 8, the exposed portion of the peripheral surface on the disk 2', and the adjacent edge of the chill ring member 49. The weld metal substantially illls the channel I3 and securely fusibly unites the bases 8 oi the blades 3 with the peripheral surface of the disk 2 and with the adjacent edge of the chill ring member 9. Next the clamping means l2 is released. the Jig withdrawn and the chill ring member 9 removed by a suitable machining or 'grinding operation to provide the circumferentially extending channel or space Il shown in Fig. 5. The channel Il is then filled with weld l as indicated in Fig. 6 and the remaining operations are to remove the excess weld metal in any suitable manner such as by machining or grinding and then to heat treat the entire assembly including the blading and spindle or rotor disk member to secure the requisite or desired physical properties.

As previously indicated, the blades 3 are arranged in row forming relation about the periphery of disk 2 with their relatively massive base portions 6 disposed in contiguous and preferably abutting relation to form a substantially continuous base ring entirely surrounding and opposing the peripheral blade mounting portion of the disk. And when the blades are thus arranged, the base portions E will function. either with or without the provision and aid of integral shroud portions such as those designated 4, to maintain the passage forming portions of the blades in correctly spaced relation. In this connection, it will be noted that the base ends of the assembled blades present an approximately continuous ring substantially equal in width to and coextensively opposing the blade mounting portion of the disk 2. And consequently, the herein disclosed method of welding the base ends of the blades to the periphery of disk 2 provides a blade assembly wherein substantially the entire base end of all of the blades are in fused union with substantially the entire coextensively opposed blade mounting portion of equal width presented by the blade supporting element. That is, a, bond of fused metal, which may and preferably does include fused portions of the blade ends and fused portions of the periphery of the rotor disk or other element, integrally unites substantially the entire base end of all of the blades with substantially the entire blade mounting portion of the element.

It should be particularly noted that in the illustrated construction the area of the underside surface of the base 8, i. e., the base end of the blade,`

is considerably greater than the area of the blade cross section taken adjacent the base B as is clearly indicated by Fig. "I, and that irrespective of whether the fused coextensive union of the base ends of the blades and the opposed peripheral blade mounting portion of a supporting element is effected by the method herein disclosed or by some other method, the effective bond area of the fused metal uniting each blade with an opposed portion of the supporting element, which area is commensurate with the area of the underside surface of the blade base 6, is therefore materially greater than the area of said blade section. In this connection, it is desirable, although not essential in all instances, to make the effective bond area of the fused metal, i. e., the cross sectional area of the weld taken on line A-A of Fig. 6, several times greater than the areaof the blade cross section taken adjacent the base thereof as is indicated by the relative size of the blade section and base shown in Fig. 7.

The blades 3 are of milled construction and the abutting surfaces of the shroud and base portions on adjacent blades are finish machined to coact and provide in eifect a sealed fluid confining passage 8. However, it should be understood that the blades 3 may be of any desired conguration and may be constructed or built-up in any 4 desired manner, that the blade assembly may be produced by methods other than that herein disproximately equal in width to the base ends of the blades secured thereto, a plurality of blades each having oppositely facing duid engaging surfaces terminating in a base portion abruptly enlarged to position and maintain the fluid engaging surfaces on adjacent blades in spaced passage forming relation and to present a single surface base end having an area materially greater than the area of the blade cross-section taken adjacent the base portion thereof, said base portion being spaced from the periphery of said disk in abutting row-forming relation with their single surfaced base ends presenting a substantially continuous plain surface disposed in opposed relation to the single surfaced periphery of said disk, and weld metal substantially lling the space between said substantialy continuous surface and disk periphery and rigidly uniting substantially all of the area presented by the base end of each of said blades with a portion of equal area presented by the opposed single surfaced periphery of said disk.

2. A turbine blade assembly comprising a turbine disk having a single surfaced periphery approximately equal in width to the base ends of the blade secured thereto, a plurality of blades each having oppositely facing fluid engaging surfaces terminating in a base portion abruptly enlarged to present a single surfaced base end having an area materially greater than the area of the blade cross-section taken adjacent the enlarged base portion thereof, said blades being positioned in adjacent row-forming relation with their single surfaced base ends presenting an approximately continuous surface disposed in spaced opposed relation to the single surfaced periphery of said disk, and weld metal substantially filling the space between said approximately continuous surface and disk periphery and rigidly uniting substantially all of the area presented by the base end of each of said blades with a portion of equal area presented by the opposed single surfaced periphery of said disk.

u3. A turbine blade assembly comprising a turbine disk having a peripheral surface approximately equal in width to the base ends of the blades secured thereto, a plurality of blades each having oppositely facing fluid engaging surfaces terminating in a relatively massive base portion abruptly enlarged to position and maintain the fluid engaging surfaces on adjacent blades in spaced passage forming relation and to present a base end having an area materially greater than the area of the blade cross-section taken adjacent the base portion thereof, said base portions being spaced from the periphery of said disk in abutting row-forming relation with their base ends presenting a substantially continuous surface disposed in opposed relation to the periphery of said disk, and weld metal substantially filling the space between said substantially continuous surface and disk periphery and rigidly uniting substantially all of the area presented by the base end of each of said blades with a portion of equal area presented by the opposed periphery of said disk.

4. A blade assemply comprising blades each having oppositely facing fluid conning surfaces terminating in an abruptly enlarged and relatively massive base portion providing an integral footing underlying substantially the entire base end portions of said uid confining surfaces and projecting laterally therefrom so as to abut the like portions of adjacent blades and maintain the fluid confining surfaces thereof in spaced passage forming relation, said blades having their base portions disposed in abutting ring-forming relation, an element presenting side faces and a continuous peripheral blade mounting portion substantially equal in width to and coextensively opposing the contiguous base end surfaces presented by the abutting massive baserportions of said blades, said abutting base portions presenting a massive body of metal separating all base end portions of said fluid confining surfaces from the peripheral blade mounting portion of said element, and a massive welded bond of fused :netal extending from one of said side faces to the other. of generally uniform thickness throughout, integrally uniting substantially the entire base end surface of the base portion of all of the blades with substantially the entire peripheral blade mounting portion of said element.

5. A blade assembly comprising an element presenting side faces and a continuous peripheral blade mounting portion, a plurality of blades each having oppositely facing fluid confining surfaces terminating in an abruptly enlarged and relatively massive base portion providing an integral footing underlying substantially the entire base end portions of said uid confining surfaces and projecting laterally therefrom so as to maintain the fluid confining surfaces of adjacent blades in spaced passage forming relation, said blades being disposed in contiguous row-forming relation with the base end surfaces of said integral footings presenting an approximately continuous ring substantially equal in width to and coextensively opposing the peripheral blade mounting portion of said element, and a massive welded bond of fused metal extending from one of said side faces to the other, of generally uniform proportions throughout, integrally uniting substantially the entire baseend surface of the base portion of all of the blades with substantially the entire peripheral blade mounting portion` of said element.

ROBERT C. ALLEN.

REFERENCES CITED The following references are of record in the iile of this patent:

UNTIED STATES PATENTS Certificate of Correction Patent No. 2,423,165.

Number Name Date 1,470,502 Steenstrup Oct. 9, 1923 2,324,011 Miller July 13, 1943 1,128,854 Coppfus Feb. 16, 1915 1,938,382 Haigh Dec. 5, 1933 2,080,425 Lysholm May 18, 1937 1,470,503l Steenstrup Oct. 9, 1923 2,174,380 Doran Sept. 26, 1939 FOREIGN PATENTS Number Country Date 214,461 Switzerland July 16, 1941 847,942 France July 17, 1939 548,649 Great Britain Oct. 19, 1942 July l, 1947.

ROBERT C. ALLEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 4, line 18, claim l, for surface read surfaced; line 21, for portion read portions; line 28, for substantialy read substantially; line 36, claim 2, for blade read blades; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of September, A. D. 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents.

area presented by the opposed periphery of said disk.

4. A blade assemply comprising blades each having oppositely facing fluid conning surfaces terminating in an abruptly enlarged and relatively massive base portion providing an integral footing underlying substantially the entire base end portions of said uid confining surfaces and projecting laterally therefrom so as to abut the like portions of adjacent blades and maintain the fluid confining surfaces thereof in spaced passage forming relation, said blades having their base portions disposed in abutting ring-forming relation, an element presenting side faces and a continuous peripheral blade mounting portion substantially equal in width to and coextensively opposing the contiguous base end surfaces presented by the abutting massive baserportions of said blades, said abutting base portions presenting a massive body of metal separating all base end portions of said fluid confining surfaces from the peripheral blade mounting portion of said element, and a massive welded bond of fused :netal extending from one of said side faces to the other. of generally uniform thickness throughout, integrally uniting substantially the entire base end surface of the base portion of all of the blades with substantially the entire peripheral blade mounting portion of said element.

5. A blade assembly comprising an element presenting side faces and a continuous peripheral blade mounting portion, a plurality of blades each having oppositely facing fluid confining surfaces terminating in an abruptly enlarged and relatively massive base portion providing an integral footing underlying substantially the entire base end portions of said uid confining surfaces and projecting laterally therefrom so as to maintain the fluid confining surfaces of adjacent blades in spaced passage forming relation, said blades being disposed in contiguous row-forming relation with the base end surfaces of said integral footings presenting an approximately continuous ring substantially equal in width to and coextensively opposing the peripheral blade mounting portion of said element, and a massive welded bond of fused metal extending from one of said side faces to the other, of generally uniform proportions throughout, integrally uniting substantially the entire baseend surface of the base portion of all of the blades with substantially the entire peripheral blade mounting portion` of said element.

ROBERT C. ALLEN.

REFERENCES CITED The following references are of record in the iile of this patent:

UNTIED STATES PATENTS Certificate of Correction Patent No. 2,423,165.

Number Name Date 1,470,502 Steenstrup Oct. 9, 1923 2,324,011 Miller July 13, 1943 1,128,854 Coppfus Feb. 16, 1915 1,938,382 Haigh Dec. 5, 1933 2,080,425 Lysholm May 18, 1937 1,470,503l Steenstrup Oct. 9, 1923 2,174,380 Doran Sept. 26, 1939 FOREIGN PATENTS Number Country Date 214,461 Switzerland July 16, 1941 847,942 France July 17, 1939 548,649 Great Britain Oct. 19, 1942 July l, 1947.

ROBERT C. ALLEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 4, line 18, claim l, for surface read surfaced; line 21, for portion read portions; line 28, for substantialy read substantially; line 36, claim 2, for blade read blades; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 2nd day of September, A. D. 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents. 

